Controlled deposition of materials using a differential pressure regime

ABSTRACT

Methods and devices for controlling pressures in microenvironments between a deposition apparatus and a substrate are provided. Each microenvironment is associated with an aperture of the deposition apparatus which can allow for control of the microenvironment.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a non-provisional of, and claims the benefit of,U.S. Provisional Patent Application Ser. No. 62/303,458, filed Mar. 4,2016, the entire contents of which is incorporated herein by reference.

PARTIES TO A JOINT RESEARCH AGREEMENT

The claimed invention was made by, on behalf of, and/or in connectionwith one or more of the following parties to a joint universitycorporation research agreement: Regents of the University of Michigan,Princeton University, University of Southern California, and theUniversal Display Corporation. The agreement was in effect on and beforethe date the claimed invention was made, and the claimed invention wasmade as a result of activities undertaken within the scope of theagreement.

FIELD OF THE INVENTION

The present invention relates to techniques for controlling depositionof materials using differential pressures, such as for deposition oforganic light emitting diodes and other devices, including the same, anddevices fabricates according to such methods.

BACKGROUND

Opto-electronic devices that make use of organic materials are becomingincreasingly desirable for a number of reasons. Many of the materialsused to make such devices are relatively inexpensive, so organicopto-electronic devices have the potential for cost advantages overinorganic devices. In addition, the inherent properties of organicmaterials, such as their flexibility, may make them well suited forparticular applications such as fabrication on a flexible substrate.Examples of organic opto-electronic devices include organic lightemitting devices (OLEDs), organic phototransistors, organic photovoltaiccells, and organic photodetectors. For OLEDs, the organic materials mayhave performance advantages over conventional materials. For example,the wavelength at which an organic emissive layer emits light maygenerally be readily tuned with appropriate dopants.

OLEDs make use of thin organic films that emit light when voltage isapplied across the device. OLEDs are becoming an increasinglyinteresting technology for use in applications such as flat paneldisplays, illumination, and backlighting. Several OLED materials andconfigurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and5,707,745, which are incorporated herein by reference in their entirety.

One application for phosphorescent emissive molecules is a full colordisplay. Industry standards for such a display call for pixels adaptedto emit particular colors, referred to as “saturated” colors. Inparticular, these standards call for saturated red, green, and bluepixels. Color may be measured using CIE coordinates, which are wellknown to the art.

One example of a green emissive molecule is tris(2-phenylpyridine)iridium, denoted Ir(ppy)₃, which has the following structure:

In this, and later figures herein, we depict the dative bond fromnitrogen to metal (here, Ir) as a straight line.

As used herein, the term “organic” includes polymeric materials as wellas small molecule organic materials that may be used to fabricateorganic opto-electronic devices. “Small molecule” refers to any organicmaterial that is not a polymer, and “small molecules” may actually bequite large. Small molecules may include repeat units in somecircumstances. For example, using a long chain alkyl group as asubstituent does not remove a molecule from the “small molecule” class.Small molecules may also be incorporated into polymers, for example as apendent group on a polymer backbone or as a part of the backbone. Smallmolecules may also serve as the core moiety of a dendrimer, whichconsists of a series of chemical shells built on the core moiety. Thecore moiety of a dendrimer may be a fluorescent or phosphorescent smallmolecule emitter. A dendrimer may be a “small molecule,” and it isbelieved that all dendrimers currently used in the field of OLEDs aresmall molecules.

As used herein, “top” means furthest away from the substrate, while“bottom” means closest to the substrate. Where a first layer isdescribed as “disposed over” a second layer, the first layer is disposedfurther away from substrate. There may be other layers between the firstand second layer, unless it is specified that the first layer is “incontact with” the second layer. For example, a cathode may be describedas “disposed over” an anode, even though there are various organiclayers in between.

As used herein, “solution processible” means capable of being dissolved,dispersed, or transported in and/or deposited from a liquid medium,either in solution or suspension form.

A ligand may be referred to as “photoactive” when it is believed thatthe ligand directly contributes to the photoactive properties of anemissive material. A ligand may be referred to as “ancillary” when it isbelieved that the ligand does not contribute to the photoactiveproperties of an emissive material, although an ancillary ligand mayalter the properties of a photoactive ligand.

As used herein, and as would be generally understood by one skilled inthe art, a first “Highest Occupied Molecular Orbital” (HOMO) or “LowestUnoccupied Molecular Orbital” (LUMO) energy level is “greater than” or“higher than” a second HOMO or LUMO energy level if the first energylevel is closer to the vacuum energy level. Since ionization potentials(IP) are measured as a negative energy relative to a vacuum level, ahigher HOMO energy level corresponds to an IP having a smaller absolutevalue (an IP that is less negative). Similarly, a higher LUMO energylevel corresponds to an electron affinity (EA) having a smaller absolutevalue (an EA that is less negative). On a conventional energy leveldiagram, with the vacuum level at the top, the LUMO energy level of amaterial is higher than the HOMO energy level of the same material. A“higher” HOMO or LUMO energy level appears closer to the top of such adiagram than a “lower” HOMO or LUMO energy level.

As used herein, and as would be generally understood by one skilled inthe art, a first work function is “greater than” or “higher than” asecond work function if the first work function has a higher absolutevalue. Because work functions are generally measured as negative numbersrelative to vacuum level, this means that a “higher” work function ismore negative. On a conventional energy level diagram, with the vacuumlevel at the top, a “higher” work function is illustrated as furtheraway from the vacuum level in the downward direction. Thus, thedefinitions of HOMO and LUMO energy levels follow a different conventionthan work functions.

More details on OLEDs, and the definitions described above, can be foundin U.S. Pat. No. 7,279,704, which is incorporated herein by reference inits entirety.

SUMMARY OF THE INVENTION

According to an embodiment, a method of depositing a material onto asubstrate includes creating a higher pressure regime in a firstmicroenvironment below a first aperture of a deposition device byejecting, from the first aperture, a delivery gas and a material to bedeposited onto a substrate; creating a lower pressure regime in a secondmicroenvironment below a second aperture located adjacent to a firstaperture; and creating a higher pressure regime in a microenvironmentadjacent to the second aperture. Material may be withdrawn from thesecond microenvironment by providing a vacuum source by way of thesecond aperture. A lower pressure regime may be created in the secondmicroenvironment, for example by withdrawing material from the secondmicroenvironment through the second aperture. A higher pressure regimemay be created in a third microenvironment below a third aperture, thethird aperture disposed adjacent to the second aperture. Similarly, alower pressure regime may be created in a fourth microenvironment belowa fourth aperture that is disposed adjacent to the first aperture andapproximately in a line with the second aperture. A higher pressureregime may be created in a fifth microenvironment below a fifth aperturethat is disposed adjacent to the fourth aperture. Each lower pressuremicroenvironment may have a pressure in the range of 75-99% of one ormore of the higher pressure microenvironment.

In an embodiment, a deposition device for depositing a material onto asubstrate includes a delivery device comprising a first aperture influid communication with a delivery gas and a source of organic materialto be deposited on a substrate, the first aperture configured to createa higher pressure regime in a first microenvironment below the firstaperture; and a second aperture, disposed adjacent to the firstaperture, and configured to create a lower pressure regime in a secondmicroenvironment below the second aperture; where the delivery devicecreates a higher pressure regime in a third microenvironment adjacent tothe second aperture. The device may include or be used in conjunctionwith a vacuum source in fluid communication with the second aperture. Athird aperture may be disposed adjacent to the second aperture, which isconfigured to create a higher pressure regime in a thirdmicroenvironment below the third aperture. A fourth aperture may bedisposed adjacent to the first aperture and approximately in a line withthe second aperture, and configured to create a lower pressure regime ina fourth microenvironment below the fourth aperture. A fifth aperturemay be disposed adjacent to the fourth aperture, the fifth apertureconfigured to create a higher pressure regime in a fifthmicroenvironment below the fifth aperture.

In an embodiment, a device for deposition of at least one material on asubstrate includes a first aperture; a second aperture adjacent to thefirst aperture; and a source of material to be deposited on a substrate,the source of material being disposed fluid communication with the firstaperture, such that when the device is in operation, a higher pressureregime exists in a first microenvironment below the first aperture, alower pressure regime exists in a second microenvironment below thesecond aperture, and a higher pressure regime exists in a thirdmicroenvironment adjacent to the second microenvironment. The device mayinclude a delivery gas source in fluid communication with the source ofmaterial to be deposited with the first aperture. The device may includea delivery gas source in fluid communication with the source of materialto be deposited with the first aperture. The device may include a thirdaperture adjacent to the second aperture, wherein, when the device is inoperation, the pressure of the third microenvironment is set via thethird aperture.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an organic light emitting device.

FIG. 2 shows an inverted organic light emitting device that does nothave a separate electron transport layer.

FIG. 3 shows an example schematic representation of an aperturearrangement according to an embodiment.

FIG. 4 shows an example schematic representation of an aperturearrangement according to an embodiment.

DETAILED DESCRIPTION

Generally, an OLED comprises at least one organic layer disposed betweenand electrically connected to an anode and a cathode. When a current isapplied, the anode injects holes and the cathode injects electrons intothe organic layer(s). The injected holes and electrons each migratetoward the oppositely charged electrode. When an electron and holelocalize on the same molecule, an “exciton,” which is a localizedelectron-hole pair having an excited energy state, is formed. Light isemitted when the exciton relaxes via a photoemissive mechanism. In somecases, the exciton may be localized on an excimer or an exciplex.Non-radiative mechanisms, such as thermal relaxation, may also occur,but are generally considered undesirable.

The initial OLEDs used emissive molecules that emitted light from theirsinglet states (“fluorescence”) as disclosed, for example, in U.S. Pat.No. 4,769,292, which is incorporated by reference in its entirety.Fluorescent emission generally occurs in a time frame of less than 10nanoseconds.

More recently, OLEDs having emissive materials that emit light fromtriplet states (“phosphorescence”) have been demonstrated. Baldo et al.,“Highly Efficient Phosphorescent Emission from OrganicElectroluminescent Devices,” Nature, vol. 395, 151-154, 1998;(“Baldo-I”) and Baldo et al., “Very high-efficiency green organiclight-emitting devices based on electrophosphorescence,” Appl. Phys.Lett., vol. 75, No. 3, 4-6 (1999) (“Baldo-II”), which are incorporatedby reference in their entireties. Phosphorescence is described in moredetail in U.S. Pat. No. 7,279,704 at cols. 5-6, which are incorporatedby reference.

FIG. 1 shows an organic light emitting device 100. The figures are notnecessarily drawn to scale. Device 100 may include a substrate 110, ananode 115, a hole injection layer 120, a hole transport layer 125, anelectron blocking layer 130, an emissive layer 135, a hole blockinglayer 140, an electron transport layer 145, an electron injection layer150, a protective layer 155, a cathode 160, and a barrier layer 170.Cathode 160 is a compound cathode having a first conductive layer 162and a second conductive layer 164. Device 100 may be fabricated bydepositing the layers described, in order. The properties and functionsof these various layers, as well as example materials, are described inmore detail in U.S. Pat. No. 7,279,704 at cols. 6-10, which areincorporated by reference.

More examples for each of these layers are available. For example, aflexible and transparent substrate-anode combination is disclosed inU.S. Pat. No. 5,844,363, which is incorporated by reference in itsentirety. An example of a p-doped hole transport layer is m-MTDATA dopedwith F₄-TCNQ at a molar ratio of 50:1, as disclosed in U.S. PatentApplication Publication No. 2003/0230980, which is incorporated byreference in its entirety. Examples of emissive and host materials aredisclosed in U.S. Pat. No. 6,303,238 to Thompson et al., which isincorporated by reference in its entirety. An example of an n-dopedelectron transport layer is BPhen doped with Li at a molar ratio of 1:1,as disclosed in U.S. Patent Application Publication No. 2003/0230980,which is incorporated by reference in its entirety. U.S. Pat. Nos.5,703,436 and 5,707,745, which are incorporated by reference in theirentireties, disclose examples of cathodes including compound cathodeshaving a thin layer of metal such as Mg:Ag with an overlyingtransparent, electrically-conductive, sputter-deposited ITO layer. Thetheory and use of blocking layers is described in more detail in U.S.Pat. No. 6,097,147 and U.S. Patent Application Publication No.2003/0230980, which are incorporated by reference in their entireties.Examples of injection layers are provided in U.S. Patent ApplicationPublication No. 2004/0174116, which is incorporated by reference in itsentirety. A description of protective layers may be found in U.S. PatentApplication Publication No. 2004/0174116, which is incorporated byreference in its entirety.

FIG. 2 shows an inverted OLED 200. The device includes a substrate 210,a cathode 215, an emissive layer 220, a hole transport layer 225, and ananode 230. Device 200 may be fabricated by depositing the layersdescribed, in order. Because the most common OLED configuration has acathode disposed over the anode, and device 200 has cathode 215 disposedunder anode 230, device 200 may be referred to as an “inverted” OLED.Materials similar to those described with respect to device 100 may beused in the corresponding layers of device 200. FIG. 2 provides oneexample of how some layers may be omitted from the structure of device100.

The simple layered structure illustrated in FIGS. 1 and 2 is provided byway of non-limiting example, and it is understood that embodiments ofthe invention may be used in connection with a wide variety of otherstructures. The specific materials and structures described areexemplary in nature, and other materials and structures may be used.Functional OLEDs may be achieved by combining the various layersdescribed in different ways, or layers may be omitted entirely, based ondesign, performance, and cost factors. Other layers not specificallydescribed may also be included. Materials other than those specificallydescribed may be used. Although many of the examples provided hereindescribe various layers as comprising a single material, it isunderstood that combinations of materials, such as a mixture of host anddopant, or more generally a mixture, may be used. Also, the layers mayhave various sublayers. The names given to the various layers herein arenot intended to be strictly limiting. For example, in device 200, holetransport layer 225 transports holes and injects holes into emissivelayer 220, and may be described as a hole transport layer or a holeinjection layer. In one embodiment, an OLED may be described as havingan “organic layer” disposed between a cathode and an anode. This organiclayer may comprise a single layer, or may further comprise multiplelayers of different organic materials as described, for example, withrespect to FIGS. 1 and 2.

Structures and materials not specifically described may also be used,such as OLEDs comprised of polymeric materials (PLEDs) such as disclosedin U.S. Pat. No. 5,247,190 to Friend et al., which is incorporated byreference in its entirety. By way of further example, OLEDs having asingle organic layer may be used. OLEDs may be stacked, for example asdescribed in U.S. Pat. No. 5,707,745 to Forrest et al, which isincorporated by reference in its entirety. The OLED structure maydeviate from the simple layered structure illustrated in FIGS. 1 and 2.For example, the substrate may include an angled reflective surface toimprove out-coupling, such as a mesa structure as described in U.S. Pat.No. 6,091,195 to Forrest et al., and/or a pit structure as described inU.S. Pat. No. 5,834,893 to Bulovic et al., which are incorporated byreference in their entireties.

Unless otherwise specified, any of the layers of the various embodimentsmay be deposited by any suitable method. For the organic layers,preferred methods include thermal evaporation, ink-jet, such asdescribed in U.S. Pat. Nos. 6,013,982 and 6,087,196, which areincorporated by reference in their entireties, organic vapor phasedeposition (OVPD), such as described in U.S. Pat. No. 6,337,102 toForrest et al., which is incorporated by reference in its entirety, anddeposition by organic vapor jet printing (OVJP), such as described inU.S. Pat. No. 7,431,968, which is incorporated by reference in itsentirety. Other suitable deposition methods include spin coating andother solution based processes. Solution based processes are preferablycarried out in nitrogen or an inert atmosphere. For the other layers,preferred methods include thermal evaporation. Preferred patterningmethods include deposition through a mask, cold welding such asdescribed in U.S. Pat. Nos. 6,294,398 and 6,468,819, which areincorporated by reference in their entireties, and patterning associatedwith some of the deposition methods such as ink-jet and OVJD. Othermethods may also be used. The materials to be deposited may be modifiedto make them compatible with a particular deposition method. Forexample, substituents such as alkyl and aryl groups, branched orunbranched, and preferably containing at least 3 carbons, may be used insmall molecules to enhance their ability to undergo solution processing.Substituents having 20 carbons or more may be used, and 3-20 carbons isa preferred range. Materials with asymmetric structures may have bettersolution processibility than those having symmetric structures, becauseasymmetric materials may have a lower tendency to recrystallize.Dendrimer substituents may be used to enhance the ability of smallmolecules to undergo solution processing.

Devices fabricated in accordance with embodiments of the presentinvention may further optionally comprise a barrier layer. One purposeof the barrier layer is to protect the electrodes and organic layersfrom damaging exposure to harmful species in the environment includingmoisture, vapor and/or gases, etc. The barrier layer may be depositedover, under or next to a substrate, an electrode, or over any otherparts of a device including an edge. The barrier layer may comprise asingle layer, or multiple layers. The barrier layer may be formed byvarious known chemical vapor deposition techniques and may includecompositions having a single phase as well as compositions havingmultiple phases. Any suitable material or combination of materials maybe used for the barrier layer. The barrier layer may incorporate aninorganic or an organic compound or both. The preferred barrier layercomprises a mixture of a polymeric material and a non-polymeric materialas described in U.S. Pat. No. 7,968,146, PCT Pat. Application Nos.PCT/US2007/023098 and PCT/US2009/042829, which are herein incorporatedby reference in their entireties. To be considered a “mixture”, theaforesaid polymeric and non-polymeric materials comprising the barrierlayer should be deposited under the same reaction conditions and/or atthe same time. The weight ratio of polymeric to non-polymeric materialmay be in the range of 95:5 to 5:95. The polymeric material and thenon-polymeric material may be created from the same precursor material.In one example, the mixture of a polymeric material and a non-polymericmaterial consists essentially of polymeric silicon and inorganicsilicon.

Devices fabricated in accordance with embodiments of the invention canbe incorporated into a wide variety of electronic component modules (orunits) that can be incorporated into a variety of electronic products orintermediate components. Examples of such electronic products orintermediate components include display screens, lighting devices suchas discrete light source devices or lighting panels, etc. that can beutilized by the end-user product manufacturers. Such electroniccomponent modules can optionally include the driving electronics and/orpower source(s). Devices fabricated in accordance with embodiments ofthe invention can be incorporated into a wide variety of consumerproducts that have one or more of the electronic component modules (orunits) incorporated therein. Such consumer products would include anykind of products that include one or more light source(s) and/or one ormore of some type of visual displays. Some examples of such consumerproducts include flat panel displays, computer monitors, medicalmonitors, televisions, billboards, lights for interior or exteriorillumination and/or signaling, heads-up displays, fully or partiallytransparent displays, flexible displays, laser printers, telephones,cell phones, tablets, phablets, personal digital assistants (PDAs),laptop computers, digital cameras, camcorders, viewfinders,micro-displays, virtual reality displays, augmented reality displays,3-D displays, vehicles, a large area wall, theater or stadium screen, ora sign. Various control mechanisms may be used to control devicesfabricated in accordance with the present invention, including passivematrix and active matrix. Many of the devices are intended for use in atemperature range comfortable to humans, such as 18 C to 30 C, and morepreferably at room temperature (20-25 C), but could be used outside thistemperature range, for example, from −40 C to +80 C.

For many deposition techniques, including OVJP and related techniques,it may be desirable to control flow of materials, deposition gases, andother fluids during deposition of materials on a substrate. For example,U.S. application Ser. No. 14/643,887, filed Mar. 10, 2015, Ser. No.14/730,768, filed Jun. 4, 2015, and Ser. No. 15/290,101, filed Oct. 11,2016, the disclosure of each of which is incorporated by reference inits entirety, disclose techniques for providing and controlling variousgas flows during deposition of organic material on a substrate. Theseand similar techniques may include, for example, the use of variousconfining gas flows to limit the region in which the organic materialmay be deposited.

Embodiments disclosed herein allow for similar control of materialsusing differential pressure regimes in different microenvironments, suchas in the region between a deposition apparatus and a substrate.

As used herein, a “microenvironment” refers to a smaller environmentthat is partially or completely contained within a larger environment,where the smaller environment has one or more properties different thanthe larger environment. For example, the region between a nozzle orother deposition aperture and the substrate on which material is to bedeposited from the aperture may be considered a microenvironment. Insome cases, a microenvironment may be a volume that does notsubstantially exchange material with surrounding volumes by diffusion.For example, two volumes of gas on either side of an active exhaustaperture would be separate microenvironments, since they would notexchange material via diffusion because any material that normally wouldmove from one to the other via diffusion would be removed by theexhaust. Conditions in separate microenvironments may be identical eventhough the microenvironments are distinct from one another, such as inthis example. In some cases, the smaller environment is defined by oneor more limitations. Examples of such properties include, but are notlimited to, a different pressure than the larger environment, adifferent pressure regime than the larger environment, a differentphysical state than the larger environment, a different temperature thanthe larger environment, a different molecular makeup than the largerenvironment. As another example, a deposition apparatus may includemultiple adjacent apertures, in which case the region between eachaperture and a substrate or, more generally, the region under eachaperture, may be considered a separate microenvironment where eachregion differs in at least one or more properties. In other cases, theregion under two or more adjacent apertures may be considered a singlemicroenvironment when there is no difference in properties betweenregions under adjacent apertures.

As used herein, the terms “high pressure” and “low pressure” refer torelative pressures between two or more environments and/ormicroenvironments. For example, a second pressure is higher than a firstpressure as disclosed herein, if the second pressure is at least theslightest value higher than the first pressure. In embodiments in whichthere are more than two apertures, the comparative pressures may bestated in reference to the first aperture. For a device having threeapertures in which the first aperture has a lower pressure in themicroenvironment below the aperture, the second aperture has a higherpressure in the microenvironment below the aperture, and the thirdaperture has a higher pressure in the microenvironment below theaperture, the pressures below the second and third apertures may be thesame, or may be different.

As used herein, an “aperture” refers to an opening in a material ordevice. As will be understood by the context herein, an aperture canhave a shape or size based on the intended use and function of theaperture. A nozzle, such as used for OVJP and similar depositiontechniques, may include an aperture at the distal end of the nozzle.Nozzles often are configured so as to eject material through such anaperture at a relatively high velocity. Such configuration may not berequired to achieve the effects and benefits disclosed herein.

As used herein, the term “adjacent” indicates that two or more featuresare proximal to one another. Adjacent apertures may be disposed directlyadjacent to one another, i.e., with no intervening apertures orfeatures, such as other features of a deposition device. More generally,two apertures may be adjacent to one another while being adjacent toother features as well, such as one or more other apertures, which maybe intervening between the two apertures. For example, when multipleapertures are arranged in a grid or other regular configuration, twointerior apertures may be adjacent to one another, while also beingsurrounded by, and adjacent to, several other apertures.

As used herein, the term “below an aperture” refers to the physicalspace between an aperture and a substrate. However, it will beunderstood that the orientation of the device or system may be adjustedso that the substrate exists spatially above the aperture relative tothe ambient environment, though the substrate and the interveningphysical space may still be described as “below” the aperture herein.

FIG. 3 shows a cross-section of a device 301 that includes an example ofan arrangement according to an embodiment disclosed herein. Thearrangement includes first and second apertures 310, 320 disposedadjacent to one another. The first aperture 310 is in fluidcommunication with a source of material to be deposited on the substrate300, such as by way of one or more vias 305 that connect to a sourcewithin, connected to, or external to the device 301. During operation,i.e., when material is ejected from the first aperture 310 toward asubstrate 300, a higher pressure regime exists in the microenvironment311 below the first aperture 310, while a lower pressure regime existsin the microenvironment 321 below the second aperture 320. The higherpressure regime in the microenvironment 311 typically will be createddue to ejection of material, carrier gases, and the like from theaperture 310 during operation. The lower pressure regime in themicroenvironment 321 may be created, for example, by the ambientenvironment, a vacuum source or other active low pressure source, suchas a source in fluid communication with the aperture 320 by way of oneor more vias 307 or the like, an exhaust or similar arrangement, or anyother suitable mechanism. In addition, a higher pressure regime existsin the microenvironment 331 adjacent to the second aperture 320 and/orto the microenvironment 321 below the second aperture. The higherpressure regime in the microenvironment 331 may be created, for example,by pressure ambient, by an active high pressure source, or any othersuitable mechanism. The arrangement of a lower pressure microenvironmentadjacent to higher pressure microenvironments may create an “inward”flow, i.e., generally in the direction of the microenvironment 311 belowthe first aperture. This in turn may define the feature size andsharpness of features deposited on the substrate 300 by material ejectedfrom the first aperture 310.

In an embodiment, an arrangement may include more than two apertures.For example, a first aperture may be surrounded by at least two adjacentapertures. That is, the two adjacent apertures may be disposed on eitherside of the first aperture. Microenvironments below the adjacentapertures may have the same or different lower pressures than themicroenvironment below the first aperture. In this way, the higherpressure regime in the microenvironment under the first aperture is atleast partially surrounded by lower pressure regime microenvironments.The apertures may be disposed in a linear arrangement, such that theylie on a straight line drawn through the first aperture and the twoadjacent apertures. Other arrangements may be used depending upon thespecific deposition shape and arrangement desired, the ambientconditions, and other factors. In some embodiments, it may be preferredthat any delivery aperture in an arrangement, i.e., any aperture that isused to eject material such as organic material toward a substrate, ispositioned adjacent to an aperture that creates a lower-pressuremicroenvironment, such as an exhaust or other low-pressure-creatingaperture.

In an embodiment, the first set of adjacent apertures including the twoadjacent apertures having the same or different lower pressure undereach adjacent aperture may be further surrounded by or otherwiseadjacent to a second set of adjacent apertures located next to the firstset of adjacent apertures. This second set of adjacent apertures mayhave microenvironments with the same or different higher pressure undereach aperture, relative to the microenvironment under the first centralaperture.

For example, in an embodiment, the first and second sets of adjacentapertures may be arranged in a linear arrangement with the first centralaperture so that, when viewed from left to right on a deposition device,the apertures are arranged as follows: second adjacent aperture(“2A”)—first adjacent aperture (“1A”)—first, or “center” aperture(“C”)—first adjacent aperture (“1A”)—second adjacent aperture (“2A”).This arrangement may be repeated, for example in a continued lineararrangement or in the perpendicular direction so as to form a grid. In aspecific linear embodiment, when viewed from left to right on a device,the apertures may be arranged as follows: 2A-1A-C-1A-2A-2A-1A-C-1A-2A.Alternatively or in addition, in some embodiments the outermostapertures and associated microenvironments may be “shared” amongadjacent sets of apertures. For example, the repeated “2A” apertures maybe replaced with a single aperture, which may have the same or differentdimensions as singular “2A” apertures. For example, in a device thatincludes a repeated pattern of apertures, the outermost “2A” aperturesmay have different arrangements than inner apertures that have otherapertures on either side. FIG. 4 shows a schematic view of such anembodiment as seen from below the device, e.g., viewed from a substrateover which the device is positioned. Each aperture shown in FIG. 4 maybe associated with one or more vias and in fluid communication withother components as previously described, for example as shown in FIG.3. As shown, one or more central apertures 410 may be adjacent to afirst set of apertures 420, which have lower pressure microenvironmentsas previously described. Similarly, these apertures may then be furtheradjacent to a second set of apertures 430. The microenvironments belowthe second set of apertures may be at a higher pressure regime comparedto the first set of aperture microenvironments and/or the centralaperture microenvironment. Such a configuration may be desirable tocreate an inward flow toward each central aperture, thereby confiningand shaping deposition of material ejected from the central apertures410 toward a substrate as previously disclosed. It may be preferred forthe outer high pressure apertures (i.e., the “2A” apertures) 430 toeject material that does not include the material that is to bedeposited on the substrate. This prevents material that is to bedeposited on the substrate from extending beyond the region on whichdeposition is desired on the substrate, and may further improve theeffect of inward flow created by the arrangement described above.

FIGS. 3 and 4 show examples of linear arrangements of apertures. Moregenerally, any pattern or order of apertures to one another may be usedaccording to the present disclosure based on the intended result, suchas the properties or arrangement of the deposited pattern of materialdeposited on the substrate. That is, the combination of high and lowpressure microenvironments may be manipulated in order to obtain adesired deposition result. Aspects of the method or device that may bemodulated, among other things, include the pressure under each aperture,the relative pressures between any two adjacent apertures, the flow rateof deposition, the flow rate of vacuum, the identity of the material tobe deposited, the carrier medium for the material to be deposited, theidentity of the substrate, the temperature of the substrate, thetemperature of the material to be deposited, the spatial arrangement ofthe apertures, the size of an aperture.

As specific examples, the pressure in the microenvironments below eachaperture as disclosed herein may be between 10 Torr and 1000 Torr, inthe range of 50 Torr to 800 Torr, in the range of 50 Torr and 760 Torr,in the range of 50 Torr and 300 Torr, or any other suitable range.Generally, a lower pressure microenvironment does not need to be at anyparticular ratio or percentage of an associated higher pressuremicroenvironment pressure. In some embodiments, it may be desirable fora lower pressure microenvironment to have a pressure of about 75-99% thepressure of an associated higher pressure microenvironment.

The aperture arrangements disclosed herein may be used in variousdifferent deposition regimes and techniques. For example, a device fordeposition by OVJP may use a nozzle block or other deposition apparatushaving an aperture arrangement as described with respect to FIG. 3 orFIG. 4. As a specific example, in an embodiment an OVJP device includesapertures arranged as follows when viewed from left to right on thedevice: 2A (higher pressure)—1A (lower pressure)—C (higher pressure)—1A(lower pressure)—2A (higher pressure). Embodiments disclosed herein maybe used to fabricate various devices, such as the OLEDs shown in FIGS. 1and 2, and other similar devices. For example, arrangements disclosedherein may be used in OVJP and similar processes.

The apertures and associated vias disclosed herein may have any suitablephysical configuration and may be fabricated and arranged withindeposition devices using any suitable techniques. For example, theconfigurations, arrangements, and techniques disclosed in U.S.application Ser. No. 14/643,887, filed Mar. 10, 2015, Ser. No.14/730,768, filed Jun. 4, 2015, and Ser. No. 15/290,101, filed Oct. 11,2016, the disclosure of each of which is incorporated by reference inits entirety, may be used in conjunction with the arrangements disclosedherein.

In some embodiments, methods of using the arrangements disclosed hereinmay include providing a higher pressure under a central (“C”) aperture,providing a lower pressure microenvironment under first adjacentapertures, and/or providing a higher pressure microenvironment undersecond adjacent apertures located adjacent to the first adjacentapertures as previously disclosed. More generally, the microenvironmentunder an aperture, and especially the relative pressure of amicroenvironment, can be controlled or modulated. The pressure of eachmicroenvironment under each aperture in a device can be separately andindependently modulated, and/or one or more microenvironments may beco-modulated or otherwise linked, such as by providing the sameconditions, placing the microenvironments into fluid communication withcommon pressure sources, or the like.

In an embodiment, deposition of materials according to the methodsand/or devices herein is used to prepare organic opto-electronicdevices, such as organic light emitting diodes (OLEDs), organicphototransistors, organic photovoltaic cells, and organicphotodetectors.

It is understood that the various embodiments described herein are byway of example only, and are not intended to limit the scope of theinvention. For example, many of the materials and structures describedherein may be substituted with other materials and structures withoutdeviating from the spirit of the invention. The present invention asclaimed may therefore include variations from the particular examplesand preferred embodiments described herein, as will be apparent to oneof skill in the art. It is understood that various theories as to whythe invention works are not intended to be limiting.

We claim:
 1. A deposition device for depositing a material onto asubstrate, comprising: a delivery device comprising a first aperture influid communication with a delivery gas and a source of organic materialto be deposited on a substrate, the first aperture configured to createa higher pressure regime in a first microenvironment below the firstaperture; and a second aperture, disposed adjacent to the firstaperture, and configured to create a lower pressure regime in a secondmicroenvironment below the second aperture; wherein the delivery devicecreates a higher pressure regime in a third microenvironment adjacent tothe second aperture.
 2. The device of claim 1, further comprising: avacuum source in fluid communication with the second aperture.
 3. Thedevice of claim 1, further comprising: a third aperture disposedadjacent to the second aperture, the third aperture configured to createa higher pressure regime in a third microenvironment below the thirdaperture.
 4. The device of claim 3, further comprising: a fourthaperture disposed adjacent to the first aperture and approximately in aline with the second aperture, the fourth aperture configured to createa lower pressure regime in a fourth microenvironment below the fourthaperture.
 5. The device of claim 4, further comprising: a fifth aperturedisposed adjacent to the fourth aperture, the fifth aperture configuredto create a higher pressure regime in a fifth microenvironment below thefifth aperture.
 6. A device for deposition of at least one material on asubstrate, the device comprising: a first aperture; a second apertureadjacent to the first aperture; a source of material to be deposited ona substrate, the source of material being disposed fluid communicationwith the first aperture; wherein, when the device is in operation, ahigher pressure regime exists in a first microenvironment below thefirst aperture, a lower pressure regime exists in a secondmicroenvironment below the second aperture, and a higher pressure regimeexists in a third microenvironment adjacent to the secondmicroenvironment.
 7. The device of claim 6, wherein a delivery gassource is in fluid communication with the source of material to bedeposited with the first aperture.
 8. The device of claim 6, furthercomprising: a delivery gas source in fluid communication with the sourceof material to be deposited with the first aperture.
 9. The device ofclaim 6, further comprising: a third aperture adjacent to the secondaperture, wherein, when the device is in operation, the pressure of thethird microenvironment is set via the third aperture.